Mexican officials were “stunned” by Trump’s tweets, AP reported. Jorge Castaneda, former foreign minister (2000-2003), told local media that Nieto “has no other choice but to say ‘I’m not going’.”

On Wednesday, Trump signed executive orders to begin preparations for construction of the wall along the Mexican border – one of the new president’s key promises from the electoral campaign.

The orders also beefed up the US Border Patrol and Immigration and Customs Enforcement, and instructed the administration to cut federal funding for “sanctuary cities” that refused to hand over illegal immigrants to law enforcement.

Trump has insisted that “Mexico would pay for the wall,” while the Mexican government has rejected any suggestion of doing so.

“I regret and condemn the decision of the United States to continue construction of a wall that, for years, has divided us instead of uniting us,” Nieto said in a brief televised message to his nation on Wednesday. Mexico “will not pay for any wall,” he said.